Various photoconductors that are selected for imaging systems, such as xerographic imaging processes, are known. These photoconductors usually contain certain photogenerating layer pigments and charge transport layer components. A problem associated with a number of the known photoconductors is that they have a minimum, or lack resistance of, to abrasion from dust, charging rolls, toner, and carrier. Further, the surface layers of photoconductors are subject to scratches, which decrease their lifetime, and in xerographic imaging systems adversely affect the quality of the developed images.
While used photoconductor components can be partially recycled, there continues to be added costs and potential environmental hazards when recycling.
In xerographic systems, extending photoreceptor life using robust layers, such as overcoats, can in some instances cause undesirable increased lateral charge migration (LCM) due to lowered wear rates and accumulation of polar and conductive chemical species on the photoconductor and friction between the cleaning blade and the photoconductor surface. Increased friction is particularly pronounced in BCR (biased charging roll) charging systems where friction forces become excessive that the torque provided by the photoconductor motor is insufficient to even turn the photoconductor drum resulting in a torque failure, thereby rendering the xerographic system and machine inoperable. Under these circumstances, the cleaning blade chips and deforms to an extent where it is non-functional and causes cleaning streaks in the xerographic developed electrostatic images.
In addition, imaging members, such as photoconductors, are generally exposed to repetitive electrophotographic cycling, which subjects the exposed charged transport layer or alternative top overcoat layer thereof to mechanical abrasion, chemical attack, and heat. This repetitive cycling causes gradual deterioration in the mechanical and electrical characteristics of the exposed photoconductor surface layer. Physical and mechanical damage during prolonged use, including the formation of surface scratch defects, are examples of reasons for the failure of belt photoconductors.
Thus, there is a need for photoconductors that substantially avoid or minimize the disadvantages of a number of known photoconductors.
Also, there is a need for wear resistant photoconductors with excellent or acceptable mechanical characteristics, especially in xerographic systems where biased charging rolls (BCR) are used.
There is also a need to improve the mechanical robustness of photoconductors or photoreceptors, and to increase their scratch resistance, thereby prolonging their service life.
Additionally, there is a need for photoconductors that possess resistance to light shock to minimize image ghosting, and minimal background shading in xerographic developed images.
There also remains a need for improved imaging members that are wear resistant, and that provide in combination excellent imaging performance and extended lifetimes, and that possess reduced human and environmental health risks.
Further, there is a need for photoconductors that abate torque failures.
Wear resistant photoconductors with excellent cyclic characteristics and stable electrical properties, stable long term cycling, minimal charge deficient spots (CDS), and acceptable lateral charge migration (LCM) characteristics, such as excellent LCM resistance, are also desirable needs.
Yet another need resides in providing environmentally acceptable photoconductor overcoat layers that contain fluoro compounds that are soluble in a number of substantially toxic free solvents thereby avoiding the uneconomical preparation and use of dispersions with compounds that have insolubility or minimum solubility in common toxic fluorinated solvents.
These and other needs are believed to be achievable with the photoconductors disclosed herein.